In the related art, ultraviolet ray irradiation apparatuses are used particularly for curing an ultraviolet curable resin that is used for bonding or the like of small-sized parts in the field of electronic components, or the like, or for curing an ultraviolet curable ink that is used in the field of printing. High-voltage mercury lamps, metal halide lamps, or the like are used for lamp light sources of the ultraviolet ray irradiation apparatuses.
When the ultraviolet light-emitting elements are used as the lamp light sources, generation of heat can be relatively suppressed. However, depending on use, a problem may occur such that heat is generated from the ultraviolet ray irradiation apparatuses, and the light emission efficiency of the ultraviolet light-emitting elements degrades due to this heat or such that the lifespan of the ultraviolet light-emitting elements becomes shorter. Thus, a device that cools an ultraviolet ray irradiation apparatus is suggested, for example, as described in Japanese Registered Utility Model No. 3158033.
However, such a device becomes a complicated and large-sized device in which there is a need for providing a cooling fan. Moreover, a large amount of heat is also generated from a constant current generation device for driving the ultraviolet light-emitting elements.